(KMSP) - An Eagan daycare provider is facing years in prison for injuring a 13-month old boy in her care. Despite already being convicted on first degree assault, the woman claims she didn’t harm the boy.

Mariel Grimm cared for the boy, named William, in her home and had been watching him since he was nine weeks old.

“I loved him like my own.” Grimm said. “When he was here, he was mine”.

On Sept 22, 2016, Grimm was changing his diaper on the floor when she says he suddenly had some kind of seizure.

“His legs got very stiff and he went like this, and just panic, sheer panic set in,” she told the Fox 9 Investigators.

According to the police report, there was no sign of trauma. At the hospital, doctors removed part of the boy’s skull to relieve the pressure on his brain.

Dr. Mark Hudson, a board certified expert in child abuse, said the boy was “not expected to survive longer than a week” and that the injuries were caused by “possible shaking or traumatic fall.”

William did, in fact, survive but is expected to suffer life-long disabilities.

EXACT CAUSE OF INJURY UNKNOWN

“We're all left with so many questions. But I know nothing happened here. He was never left alone with my kids. There was never an accident of any kind. I was watching him and he slept most of the day,” Grimm said.

She believes his injuries happened at his home.

The boy's parents told police their son had “bonked” his head at home three times the day before, including when he fell and hit the back of his head on a wood floor.

At Grimm’s trial in July, expert witnesses couldn't say exactly how the injury occurred and disagreed on when.

Dr. Donald Chadwick, a pediatric neurologist, said CT scans show the injury was mostly on the left side of the brain, unusual in a shaken baby case and they may have happened before the child reached daycare.

But Dr. Mark Hudson testified “the symptoms would have been apparent immediately after he suffered head trauma,” after he had been dropped off at daycare.

Dr. Hudson also said such head trauma from a short fall was, “exceedingly unlikely.”

A jury found Grimm guilty of first degree assault.

“HUDSON’S TESTIMONEY WAS ‘KEY’”

“I know the character of my wife. I know that she would never do something like this,” said Grimm’s husband, Andy. He added that he thought Hudson’s testimony was “key” in the trial.

Hudson is the director of the Midwest Children’s Resource Center of Children's Hospital, which specializes in child abuse, and he's become the go-to expert for police and prosecutors.

Hudson did not respond to a request for comment. There have been questions about his cases before.

Last year, the Fox 9 Investigators introduced you to DeClara Tripp and her son Zhakari. Dr. Hudson said the boy was also violently shaken. His mother is still fighting for custody.

“I held him in my hands, called 911, breathed in his mouth and rubbed on his chest. He goes, “huhhhh,” DeClara said. “My son was not abused. I know he was not left unattended to get abused. I know that.”))

Shari and Rick Smith were also accused of child abuse. Their daughter, Mariah, was only nine months old when she fell and hit her head on an end table.

Hudson called it abusive head trauma.

After $15,000 in legal fees and passing a lie-detector test, the case was quietly dropped.

HOW SBS IS DIAGNOSED

The classic symptoms used to diagnose “shaken baby syndrome,” or “abusive head trauma” are:

Subdural hematoma - when blood fills the space between the brain and skull.

Cerebral edema - swelling of the brain.

Retinal hemorrhages - bleeding in the back of the eye.

In William's case, there was no evidence of retinal hemorrhaging.

“If you don't need evidence of injury to accuse, how do you defend yourself?,” Asked Dr.Janice Ophoven, a forensic pathologist.

There's now a growing chorus of forensic pathologists who are questioning the diagnosis of shaken baby syndrome.

"I've seen so many families ruined by what I consider false accusations,” said Dr. Jan Leestma, a neuropathologist based in Chicago.

New research has found a wide variety of possible causes for those same three symptoms, like accidental trauma, congenital malformations, metabolic disorders, birth defects and so on.

Now, bio-mechanics are adding to the skepticism.

The Washington Post conducted an experiment with baby dummies and found a grown man shaking a 22-pound baby generated only six G’s of force, while a short fall can generate more than 10 times the force of shaking alone.

“I get these cases, where's the trauma? Where the evidence is this child suffered an impact? If you have those three I don't have to think,” Ophoven said.

SENTENCING SET

Detectives admit Grimm hasn’t changed her story. The case against her is circumstantial.

She is scheduled to be sentenced on Thursday, September 28. She’s facing eight years in prison.

The defense is asking that the verdict be set aside and Grimm be given a new trial, arguing the evidence was not established to a reasonable degree of medical certainty. More than 50 people have written letters of support for her.